SD2M with Multi-Level Technology
For the power range > 100 kW and a rotating field frequency up to 2,000 Hz
The new frequency converter SD2M is designed for high-speed applications with high output powers. Beside exceptionally low rotor losses as well as reduced motor heating, the device offers new opportunities in motor design on account of the high rotating field frequencies.
SIEB & MEYER has developed a converter for motor and generator operation of high-speed applications with high output powers. Owing to the innovative three-level technology the device can work with higher switching frequencies as well as higher motor speeds or a greater number of poles. Especially the opportunity to use motors with more poles makes the motor design in this power/speed range much more flexible. Besides, good current quality is always provided so as to generate lowest possible losses in the motor – this prevents excessive motor heating and reduces the bearing load. As a rule, the efficiency of the complete system increases.
The firmware of the new device is based on that of the well-proven series SD2S by SIEB & MEYER. To accommodate multi-level technology though, the existing control algorithms and models for sensorless operation of synchronous and asynchronous motors required some adapting. Therefore, the developers changed the structures and codes of these software parts noticeably. In addition, the interfaces implemented in the hardware were also realized in the firmware by the experts in Lueneburg. The first development stage with the new device technology and a rated power of 160 kW has reached market maturity now. At the same time SIEB & MEYER already develops a variant with 250 kW.
Up to now converters for output powers > 100 kW and rotating field frequencies > 2,000 Hz were not available on the market – let alone solutions also capable of controlling synchronous motors without sensor. The main reason for this is the challenge with respect to the motor design and the resulting heat dissipation. However, due to the German turnaround in energy policy such systems with synchronous motors are in demand – they provide the required power density and efficiency to make a significant increase in the efficiency of regenerative systems possible. These are rotating energy storage units (flywheel) and turbomachinery like turbo compressors and other compressors, e.g. for waste water treatment systems or ORC systems to convert waste energy into electric energy.
The development project is funded by the German Federal Ministry for Economic Affairs and Energy.